December 2014 – Page 2 – My Chicago Botanic Garden

The Long Road Home

Golden paintbrush (Castilleja levisecta) is gaining ground in its native Oregon for the first time in more than 80 years. Recent reintroductions have seen the charismatic species flourish on its historic prairie landscape. To keep the momentum going, scientists are pulling out all the stops to ensure that the new populations are robust enough to endure.

“Genetic variability will be key to the reintroduction success of golden paintbrush,” explained Adrienne Basey, graduate student in the plant biology and conservation program of the Chicago Botanic Garden and Northwestern University.

PHOTO: Golden paintbrush (Castilleja levisecta). — Golden paintbrush (*Castilleja levisecta*) growing in propagation beds in Oregon. Photo by Tom Kaye

Basey, who previously managed a native plant nursery, is now studying the genetic diversity of golden paintbrush plants before, during, and after they are grown in a nursery prior to reintroduction to the wild.

“My work is looking at the DNA, or genetics, of the wild, nursery, and reintroduction populations to see if there is any change through that process,” she said. If there is a change, she will develop recommendations for adjusting the selection and growing process to better preserve diversity. “My goal is to give both researchers and practitioners more information to work with,” she noted.

Building for the Future

The research is unique in the relatively young field of restoration science, according to Basey’s co-advisor and molecular ecologist at the Garden, Jeremie Fant, Ph.D. “Adrienne’s study is awesome because of the fact that it has data and the samples to back it up; it is early on in this game of reintroductions and restorations, and potentially could have a lot of impact, not just for that species but what we tell nurseries in the future,” he said.

PHOTO: Adrienne Basey with herbarium specimens. — Basey works with herbarium specimens

Basey is working with data collected over the past decade by research scientists at the Institute for Applied Ecology in Corvallis, Oregon, and University of Washington herbarium specimens from Washington and Oregon dating as far back as the 1890s, and data she has collected from existing plants during field work. “It’s a perfect partnership,” said Dr. Fant, who noted that the Garden is guiding the molecular aspect of the study while colleagues in Washington and Oregon are providing a large portion of the data and samples.

The availability of all of this information on a single species that is undergoing restoration is very rare, explained Fant. “It’s a very unique scenario that she has there, so we can look at how diversity changes as we go from step to step and hopefully identify any potential issues and where they are occurring in the process.”

The study itself will likely serve as a research model for other species in the future. “There isn’t much research out there to help propagators understand when and where genetic diversity may be lost during the production process,” said Basey’s co-advisor and conservation scientist at the Garden, Andrea Kramer, Ph.D.

Last year, Basey, Fant, and Kramer worked together to write a paper outlining ten rules to maximize and maintain genetic diversity in nursery settings. “My goal is to support reintroduction efforts by informing nursery practices and demonstrate to nurseries on a broader scale how their practices can influence genetic diversity through a single case study,” said Basey.

A Green Light Ahead

Her preliminary research is focused on four golden paintbrush populations. Early evaluations show clear distinctions between a few of them, which is good news. Basey will next compare those genetic patterns to those of plants in reintroduction sites.

According to Fant, earlier studies by other researchers have shown that many restoration efforts for threatened species suffer from low levels of genetic diversity prior to reintroduction, due to a number of causes ranging from a small population size at the outset to issues in propagation. It is critical to work around those issues, he explained, as the more genetic diversity maintained in a population, the better equipped it is to survive environmental changes from drought to temperature shifts.

Basey will also compare the current level of diversity of golden paintbrush to that of its historic populations, to get a better sense of what the base level should be for reintroduction success. She plans to wrap up her lab work well before her summer 2015 graduation date.

PHOTO: A golden paintbrush is visited by its primary pollinator, a bumblebee. — A golden paintbrush is visited by its primary pollinator, a bumblebee.

For now, she is pleased with the level of diversity she sees in the current population. “I think the fact that it has a high genetic diversity means that these reintroductions could be successful,” she said. “But if we are creating a bottleneck, we need to know that so we can mitigate it as quickly as possible.” (A bottleneck is an event that eliminates a large portion of genetic variability in a population.)

Fant is enthusiastic about the timing of the study as the field of restoration is taking off. “We can jump in early as programs are being started,” he noted. “If we all learn together, I think it really does ensure that everyone gets what they need in the end.”

For Basey, it’s about building a bridge between the theoretical and the applied aspects of restoration. “My interest isn’t so much in this single species but more in the communication of science to practitioners. I like to bridge the line between research and the people who are using research,” she said.

Basey, like the golden paintbrush, is looking toward a bright future.

Seeking out the Elusive Wild Phlox

Recently I had the pleasure of speaking at a symposium on plant exploration that was held in Des Moines, Iowa. The audience was enthralled following the plant collecting exploits of such luminaries as Dan Hinkley, one of the founders of the renowned (alas, no more) Heronswood Nursery, to far-flung locales such as Vietnam, China, and Bhutan.

Much of my presentation focused on plant collecting a tad closer to home—not as exotic perhaps, but still crucial in support of my research as the Chicago Botanic Garden’s plant breeder. So let’s go seek out the elusive wild phlox.

Phlox is predominantly a North American genus (one species sneaks into Siberia) best known for its gaudily—some say garishly colored—harbinger of spring, the moss phlox (Phlox subulata), and for that summer stalwart, the garden phlox (Phlox paniculata). For an idea of the diversity of the garden phlox, you can see Richard Hawke’s latest evaluation report on Phlox paniculata cultivars. The woodland phlox (Phlox divaricata) and the meadow phlox (Phlox maculata) also have their selections and garden advocates. It’s likely that every midwestern gardener has a phlox or two in their landscape.

Most of the remaining 60-plus phlox species are relatively unknown to horticulture, yet can delight the senses with their almost infinite variation of flower color and fragrance. The underutilized species are admittedly a persnickety group to cultivate, with many of them inhabiting harsh habitats from baking desert valleys to frigid alpine rock outcrops. So phlox breeding efforts in the past have focused (and rightly so) on the more amenable-to-cultivate species mentioned above.

My breeding work at the Garden has always focused on developing new garden plants from interspecific hybridization, or crossing different species in the same genus. I’ve used this approach to develop new coneflowers (Echinacea) and false indigos (Baptisia), to name a few. In 2006, I started assembling a collection of phlox with the intent of testing my luck in creating novel hybrids between the species here as well. The botanical and horticulture literature wasn’t too encouraging on this front, with perhaps about a dozen authenticated natural and man-made interspecific hybrids known to date. But my perseverance led to two interspecific hybrid phlox, which gardeners may be able to purchase in 2015: Phlox x procumbens ‘Pink Profusion’ and Phlox ‘Violet Pinwheels’.

PHOTO: Pink Profusion phlox. — *Phlox* × *procumbens* ‘Pink Profusion’ PPAF

PHOTO: Violet Pinwheels phlox. — *Phlox* ‘Violet Pinwheels’ PPAF

You may ask,“And where is the plant exploration in this story?” I’m getting there!

Most of the phlox species simply aren’t available in the horticulture trade, yet I desired them for my breeding program. So commencing in 2011, I started my own plant collecting efforts to locate, study, and collect species phlox in the wild. Weeks were spent pouring over old taxonomic literature, maps, herbarium records and the like just to find out where phlox may yet exist in the wild. I say “may,” as the earliest records I located were from the 1940s—never a good harbinger, as urban sprawl, agriculture, and the like all too often swallow up such older stands of native plants. But records from recent years gave me strong hope that some phlox species are still “out there.” Modern collections invariably include GPS coordinates in their notes. Google Earth became my friend at this time, helping to locate potential collecting sites and plan out my trips.

PHOTO: Jim Ault in Russia. — On a trip a few years ago, a bit further afield: an expedition in Russia with colleagues

Finally: boots on the ground! I’ve made local trips around northern Illinois and Indiana, and trips further afield to South Dakota, Idaho, Montana, Wyoming, and Nevada. I’ve settled into a now-familiar routine. Do my research ahead of time, as above. Then go locate the plants in bloom, which translates into days of cruising bumpy, muddy, delightfully scenic and isolated dirt roads out west with one eye on the curves and drop-offs ahead and the other on the disturbed road edges, where so many phlox tend to congregate. Phlox as a rule are resentful of heavy plant competition, and so ironically, often thrive on road edges where the occasional mower or bulldozer damage clears out the competitors. It is that or scramble up steep cliffs and talus slopes, or venture out on to harsh alkaline flats, where yet again the plant competition is light, allowing phlox to thrive.

PHOTO: Haemanthus aliblos in vitro specimen. — Another project in vitro: *Haemanthus aliblos* specimen
Photo by Jim Ault

As I find populations with plants that appear promising for cultivation, I record field notes and GPS readings, then return in another month or year with collecting permits in hand to collect seed or cuttings. Slowly, I have been building collections of several phlox species, with the hope of ultimately combining through breeding their traits of varied flower shapes, color, and fragrance, plant habits, and adaptability for cold, heat, drought, moisture, high pH, and salinity. Phlox typically take two years from a rooted cutting or a germinated seed to grow into a flowering-sized plant, so the process of growing the species and then using them in breeding is taking time. But this year marked the first I saw a significant number of plants bloom that were hybrids made between garden cultivars and wild-collected plants. As is typical in plant breeding, most of the plants were “dogs” with terrible flowers or habits, or poorly adapted to our local garden conditions. These all got the heave-ho to the compost pile. But a few gems stood out. Stay tuned for future updates!

Working to restore a rainbow of wildflowers in the Colorado Plateau

I’m a conservation scientist here at the Chicago Botanic Garden. I have an incredible job that allows me to work with many wonderful graduate students and a team of researchers to study ways to restore natural areas in the Colorado Plateau.

If you’ve ever visited national parks like the Grand Canyon or Arches, you’ve experienced at least some of what the Colorado Plateau (also known as the Four Corners region) has to offer. It includes more than 80 million acres across Utah, Colorado, New Mexico, and Arizona—and the largest concentration of national parks in the country.

PHOTO: Andrea Kramer in the Colorado plateau. — Our research team heads out across a recently-burned area in search of data.

Although beautiful, the Colorado Plateau’s natural areas are facing many threats, including wildfires, a changing climate, and destructive invasive species such as cheatgrass (Bromus tectorum) and Russian knapweed (Acroptilon repens). Working with many partners, including the Bureau of Land Management, we are studying which native plants may be best able to handle these growing threats (we refer to them as “native winners”). The ultimate goal is to help make restoration of these plants and habitats as effective as possible in order to maintain healthy natural areas that support wildlife and pollinators, and help keep our air and water clean.

PHOTO: Andrea Kramer at Rio Mesa. — Another beautiful day at Rio Mesa

This is no small task. The invasive species that the native plants are up against are very impressive. For example, Russian knapweed is allelopathic (prevents other plants from growing nearby), and it has roots that can grow more than 20 feet deep, seeking the water table. Fortunately, some native species are also able to grow in these conditions, and some even appear to be evolving and adapting to be better competitors.

Three Northwestern University graduate students are working with me. Master’s student Nora Talkington is testing how different populations of a native grass are able to compete with Russian knapweed, while doctoral student Alicia Foxx is researching how different root structures of native plants help them compete with invasive species. Master’s student Maggie Eshleman is studying six native wildflower species including the smallflower globe mallow (Sphaeralcea parvifolia), which has tiny, fiery orange flowers. These wildflowers are likely “native winners” and are strong candidates for increased use when restoring habitat in the Colorado Plateau.

A rainbow of wildflowers for restoration:

Tansy aster (Machaeranthera canescens): This purple-flowered plant is good for pollinators, one of the few plants that flowers late in the season, and on top of that, is really good at growing in sites that need to be restored.
Woolly plantain (Plantago patagonica): This cute little annual plant is often the only thing we find flowering and producing seeds during extreme drought years. It is very impressive!
Bee plant (Cleome lutea): This annual plant has gorgeous yellow flowers. It’s good at growing in disturbed areas and, as its name indicates, is a great forage plant for bees.

PHOTO: Cleome lutea. — Bee plant (*Cleome lutea*) by Andrea Kramer

PHOTO: Sphaeralcea parvifolia. — Smallflower globe mallow (*Sphaeralcea parvifolia*) by Andrea Kramer

PHOTO: Machaeranthera canescens. — Tansy aster (*Machaeranthera canescens* or *Dieteria canascens*) by Maggie Eshleman

PHOTO: Plantago patagonica. — Woolly plantain (*Plantago patagonica*) by Andrea Kramer

This summer was a busy one. My students and I spent many weeks in the Colorado Plateau working with collaborators to collect seeds (as part of Seeds of Success collectors—a national native seed collection program). These seeds are now being used for studies in the Garden’s research greenhouses and growth chambers, and at study plots in Utah, Arizona, and Colorado. In the Garden’s Daniel F. and Ada L. Rice Plant Conservation Science Center, we are also using incubators to create spring- and summer-like conditions that will help us understand when and why seeds of certain species are able to germinate and grow. This is an important aspect of ultimately being able to restore species in a degraded habitat.

PHOTO: La Sal mountains in the background; the plains abloom in May. — La Sal mountains in the background; the plains abloom in May

How cool is it to be able to take research that’s been done on a small scale and actually apply it to the real world? I feel so lucky to be able to do this work, and being here at the Chicago Botanic Garden has allowed me to build long-term partnerships that investigate the application of research, rather than just focusing on publishing it. Stay tuned for updates on how these native winners perform.

This post was adapted from an article by Nina Koziol that appeared in the winter 2014 edition of Keep Growing, the member magazine of the Chicago Botanic Garden.

Making Topiary Trees for Wonderland Express

Imagine a winter landscape: White birches reflect the December sun. Snow drifts around the bare trunks. A glaze of ice gives a silvery cast to evergreens. Such a scene was the inspiration for the topiary trees designed by the horticulture staff for this year’s Wonderland Express.

PHOTO: Finished topiary tree. — *Tillandsia* ‘Black Beauty’, *Cryptanthus* ‘Pink Starlight’ and ‘Ruby’, and the spoon-shaped succulent leaves of *Cotyledon* ‘Orbit’ make up this 3-foot topiary.

The popular holiday event, with its indoor model train display and miniature replicas of Chicago-area landmarks, offers something for visitors of all ages and interests. The topiary room in Joutras Gallery recreates a winter scene from plants you don’t typically see in holiday arrangements. Drifts of white poinsettias resemble an undulating snowfall, and the frosty evergreens are constructed from hundreds of diverse air plants and succulents. The result is an unusual horticultural presentation that feels both wintry and alive.

The display may also give visitors ideas for incorporating different types of plants into their home holiday décor. Hens and chicks, Tillandsia, aloe, mother-in-law tongue, and agave can all be incorporated into beautiful arrangements to last all winter. Construction of a basic topiary tree is relatively simple, and gardeners looking for an indoor project might consider creating a tabletop topiary for their home.

Here’s how we did it:

Liz Rex stuffing the topiary tree frame — Bags of styrofoam peanuts fill the tree frame, covered by a layer of sphagnum moss. You’ll want gloves for the moss—it can be pointy, and a skin irritant.

Stuff it! We started by stuffing cone-shaped frames with bags of styrofoam peanuts. The bags have some give and are relatively lightweight, yet help anchor the plants used to cover the frame. The topiary forest in the Joutras Gallery has a central tree standing 8 feet tall, surrounded by six smaller trees. For the biggest trees we used Sansevieria trifasciata ‘Moonshine’, Sansevieria parva, Cryptanthus fosterianus ‘Elaine’, and Euphorbia stenoclada. A tabletop tree for the home could stand 12 to18 inches tall, and be composed of more delicate air plants (Tillandsia).
It’s a wrap! We took fishing line and wound it around the frame to create a grid for extra support.
Gather moss. Next, we covered the frame with handfuls of sphagnum moss. The moss medium holds moisture needed to keep the plants healthy and happy. If you’re trying this at home, it’s a good idea to wear plastic gloves when handling the moss. You can also use floral oasis foam cut to shape as an alternative to the frame and moss.
Insert plants. We used floral wire and sod staples to poke plants through the moss and into the Styrofoam. For smaller plants, such as the Tillandsia, wrap the wire in an inconspicuous place at the base of the plant, and twist the ends into a pick. Larger plants are held in place with the staples inserted at an angle and hidden by the foliage. Start at either the top or the bottom and work in one direction. Plants should be touching, but not completely overlapping. Place a few plants, step back and look at your work. Your eye will tell you if the plants are too sparse, overcrowded or just right. Spanish moss can help fill in any remaining gaps.
Have fun! Topiary trees allow you to be creative with live plants, and make something really special for your home. The arrangements can last for months if you spritz them with water, and protect them from light and temperature extremes.

The jagged white and green stripes of Aloe ‘Delta lights’ contrast with thin-leaved Agave gemniflora and a purple-edged Agave ‘Blue Glow’.

Looking for great combinations to try at home? Here’s what we used:

The 3-foot trees:

Tillandsia juncea
Garland Tillandsia abdita

Cotyledon ‘Orbit’
Cryptanthus ‘Ruby’
Cryptanthus ‘Pink Starlight’
Tillandsia ‘Black Beauty’

The 4-foot trees:

Tillandsia harrisii
Tillandsia juncea
Cryptanthus ‘Pink Starlight’

Sempervivum ‘Purple Beauty’
Sempervivum tectorum ‘Pilioseum’
Agave ‘Rasta Man’
Tillandsia bergeri
Kalanchoe tomentosa

The 6-foot trees:

Aloe ‘Delta lights’
Agave ‘Blue Glow’
Agave gemniflora
The starburst on top is Euphorbia stenoclada

Sansevieria trifasciata ‘Moonshine’
Agave gemniflora
Agave ‘Blue Glow’
Aloe ‘Delta Lights’
Kalanchoe tomentosa
Agave ‘Rasta Man’
Haworthia fusciata
Sempervivum ‘Purple Beauty’
Several different kinds of Tillandsia

The 8-foot tree:

Sansevieria trifasciata ‘Moonshine’
Sansevieria parva
Cryptanthus fosterianus ‘Elaine’
Euphorbia stenoclada